The American healthcare system has begun to embrace strategies to improve safety, and the obstetrical community has been put on notice due to steadily increasing rates of severe obstetrical complications. Given that childbirth is the number one reason for hospitalization in the U.S., at over 4 million births per year, determining a strategy to address this increasing morbidity has become paramount. Improved neonatal outcome as a result of successful regionalization of neonatal intensive care has prompted policy makers to examine the feasibility of creating obstetrical levels of care in parallel to these neonatal levels, so that mothers with high-risk pregnancies could deliver at hospitals with the appropriate resources, e.g. the availability of sub-specialists, specialty intensive care units, blood banking services, and diagnostic imaging equipment to optimize outcomes and limit maternal morbidity. Here, we propose the following specific aims: Specific Aim 1) Using guidelines for perinatal services generated by professional organizations as a foundation for creating hospital levels of obstetrical care, we will describe these levels of obstetrical care as they currently exist in California's childbirth hospitals; Specific Aim 2) We will test whether the obstetrical levels of care identified in Aim 1 are associated with improved maternal and newborn outcomes for deliveries in various risk groups, and to determine if additional hospital characteristics, staffing and practice patterns may contribute to these differences; and Specific Aim 3) We will quantify the amount of maternal and neonatal morbidity that might be preventable if deliveries were carried out a) at hospitals with the optimal level of care for the specific group, and b) at hospitals with the optimal combination of both levels of care and clinica practice patterns. We theorize that improvements may not only be related to obstetrical levels of care, but likely will also include hospital policies and practices, staffing availability, performace improvement activities, and staff educational programs. Utilizing survey of California childbirth hospitals regarding their facilities, resources, policies, and practices, and a database linking al hospital discharge data for mothers and newborns, the research team will employ its previously developed qualitative and quantitative methodologies to identify hospital characteristics associated with obstetrical levels of care, to measure obstetrical outcomes, and to characterize the policies and practice patterns associated with these obstetrical outcomes. Our intention is that these data would assist the obstetrical and public health communities in determining whether there is evidence that improvement in maternal outcomes might be expected from establishing regional obstetrical levels of care vs. developing more accessible, standardized institutional specific guidelines and resources and/or more effective benchmarking strategies.